Herein, we report the preparation and characterization of hybrid polysulfone/wood flour/nanoclay (PSWF/nanoclay) nanocomposite films prepared by solution casting at room temperature and characterized by FT-IR spectroscopy, SEM, X-ray diffractometry, and TGA. Long-term water-absorption and diffusion properties were determined by immersing the composites in water at room temperature for several weeks. Water absorption decreased with increasing nanoclay loading, while superior mechanical properties were observed with the addition of nanoclay particles. Furthermore, the ability of the PSFW/phosphonium-salt-modified-bentonite (PSFWBP) nanocomposite to adsorb methylene blue (MB) from water was studied in detail; more MB was adsorbed at higher pH, longer contact times, and higher PSFWBP loadings; however, higher temperatures detrimentally affected adsorption. Adsorption obeyed pseudo-second-order kinetics, with Delta H, Delta S, and Delta G determined to be -36.3 +/- 0.5 kJ mol(-1), -114.3 +/- 0.72 J mol(-1) K-1, and -2.81 +/- 0.08 kJ mol(-1) (at 293 K), respectively. PSFWBP efficiently removed MB from various real samples.